What You Did
You tested the ripening of certain fruits, either peaches, plums, or avocados.
You should have noticed that one of your methods ripened your fruit faster than the others. If your fruits were all about the same ripeness at the start, the fruit in the bag with a banana should have ripened relatively quickly, the one at room temperature somewhat slowly, and the one in the refrigerator probably didn’t ripen at all.
If you didn’t use fruits that were under-ripe at about the same amount, your experiment may have produced different results.If your banana isn’t very ripe, the one in the bag will take longer to ripen.
Try all kinds of fruit. Try different locations around your house, or even outside